The overall goal of the Molecular Biology Core of this Alcohol Research Center is to study the association between specific genes and various aspects of alcoholism, alcohol abuse and alcoholic organ complications. The Core has developed polymerase chain reaction (PCR)-based genotyping assays for the alcohol metabolizing enzymes, ADH2, ADH3, and ALDH2 and has determined the allele frequencies of these loci in various collaborative studies. We will continue to offer these genotyping services to investigators in order to determine if there are further relationships between these enzymes and responses to alcohol. A new focus of the core is to establish new genotyping methods for other alcohol metabolizing enzymes, endorphins, and the genes related to dopamine and serotonin synthesis, degradation and neurotransmission. The restriction fragment length polymorphism (RFLP) assay or PCR analysis of polymorphic repetitive DNA sequences will be employed on genes for which polymorphisms are known. If a new mutation in a gene of interest is found or reported, we will develop a PCR-based genotyping assay instead of the RFLP analysis because it requires less DNA and the assays are easier to interpret. For genes in which polymorphisms are not yet known, we will search for polymorphic CA repeats or alternatively, amplify exons and/or introns and screen for single strand conformation polymorphisms in order to develop genotyping assays.